STAT6 and solitary fibrous tumor: In recent studies, NAB2-STAT6 or NFIX-STAT6 fusion gene was reported to be the driver mutation of SFT, which plays a key role in collagen production, vessel formation, and tumor proliferation[3,4,6]; however, the IHC staining of preoperative STAT6 staining for breast SFTs are seldom reported, possibly due to its rarity.